Diffractive Alvarez lens

Barton, Ian M.; Dixit, S.; Summers, L.T.; Thompson, Charles A.; Avicola, K.; Wilhelmsen, J.

doi:10.1364/ol.25.000001

Cited by 53 publications

(24 citation statements)

References 2 publications

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“…These elements have been shown to exhibit increased depth of focus 10, 11 , and in tandem, they can form an aberration-correcting lens with adjustable focus called the Alvarez lens 12, 13 . Many methods of realizing freeform optical elements, and in particular cubic surfaces, have been suggested and implemented, including fluid-filled 14 , custom single-point diamond turned polymer 15 , and diffractive optical elements 16 . Unfortunately, diffractive optics and single-point diamond turned elements often require complex and expensive fabrication, such as greyscale or multistage lithography or machining procedures ill-suited for large-scale production.…”

Section: Introductionmentioning

confidence: 99%

Metasurface Freeform Nanophotonics

Zhan

Colburn

Dodson

et al. 2017

Sci Rep

103

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Freeform optics aims to expand the toolkit of optical elements by allowing for more complex phase geometries beyond rotational symmetry. Complex, asymmetric curvatures are employed to enhance the performance of optical components while minimizing their size. Unfortunately, these high curvatures and complex forms are often difficult to manufacture with current technologies, especially at the micron scale. Metasurfaces are planar sub-wavelength structures that can control the phase, amplitude, and polarization of incident light, and can thereby mimic complex geometric curvatures on a flat, wavelength-scale thick surface. We present a methodology for designing analogues of freeform optics using a silicon nitride based metasurface platform for operation at visible wavelengths. We demonstrate a cubic phase plate with a point spread function exhibiting enhanced depth of field over 300 micron along the optical axis with potential for performing metasurface-based white light imaging, and an Alvarez lens with a tunable focal length range of over 2.5 mm corresponding to a change in optical power of ~1600 diopters with 100 micron of total mechanical displacement. The adaptation of freeform optics to a sub-wavelength metasurface platform allows for further miniaturization of optical components and offers a scalable route toward implementing near-arbitrary geometric curvatures in nanophotonics.

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Section: Introductionmentioning

confidence: 99%

Metasurface Freeform Nanophotonics

Zhan

Colburn

Dodson

et al. 2017

Sci Rep

103

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“…Over the past few years, both refractive and diffractive solid tunable lenses based on the Alvarez-Lohmann principle have been experimentally demonstrated. (54)(55)(56)(57) The first solid tunable lens based on the Alvarez principle, working in a diffractive manner, was experimentally achieved using photolithography in 2000. (54) Such a lens consists of two phase plates with 16 phase levels, fabricated by standard multistep photolithography and then tested with an interferometer.…”

Section: Prototypes Of Solid Tunable Lenses With Various Driving Mechmentioning

confidence: 99%

“…(54)(55)(56)(57) The first solid tunable lens based on the Alvarez principle, working in a diffractive manner, was experimentally achieved using photolithography in 2000. (54) Such a lens consists of two phase plates with 16 phase levels, fabricated by standard multistep photolithography and then tested with an interferometer. The results show that aberrations owing to fabrication and assembly errors are controlled to be under 0.1λ, which guarantees an excellent performance of the lens applied in laser systems.…”

Section: Prototypes Of Solid Tunable Lenses With Various Driving Mechmentioning

confidence: 99%

Miniature Solid Tunable Lenses and Their Applications: A Review

Yongchao¹,

Siong²,

Guangya³

2017

Sensors and Materials

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We present a systematic review of solid tunable lenses based on the Alvarez-Lohmann principle, which mainly focuses on the optimization, miniaturization, and integration of such solid tunable lenses in miniature applications. The progress of the modelling and design methods of such solid tunable lenses for optimum performance is summarized first. The development of various solid tunable lenses achieved using diverse driving mechanisms and different optimization methods is then illustrated by examples from current literature. The mechanisms, performance, and practicability of all these prototypes are presented in detail. The applications of such solid tunable lenses in miniature imaging systems are finally reviewed. Discussions of the problems and bottlenecks encountered in current research work and perspectives for future work in this field are given.

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“…A further dual-optic IOL, based on the Alvarez lens principle, 116 rather than optic shift, is in the early stages of development. The Turtle IOL 117 inserted into the capsule, features a mechanical frame encasing two lenses that rotate in response to ciliary muscle contraction, causing a change in their combined optical power.…”

Section: Turtlementioning

confidence: 99%

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

Sheppard

Bashir

Wolffsohn

et al. 2010

Clinical and Experimental Optometry

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The correction of presbyopia and restoration of true accommodative function to the ageing eye is the focus of much ongoing research and clinical work. A range of accommodating intraocular lenses (AIOLs) implanted during cataract surgery has been developed and they are designed to change either their position or shape in response to ciliary muscle contraction to generate an increase in dioptric power. Two main design concepts exist. First, axial shift concepts rely on anterior axial movement of one or two optics creating accommodative ability. Second, curvature change designs are designed to provide significant amplitudes of accommodation with little physical displacement. Single-optic devices have been used most widely, although the true accommodative ability provided by forward shift of the optic appears limited and recent findings indicate that alternative factors such as flexing of the optic to alter ocular aberrations may be responsible for the enhanced near vision reported in published studies. Techniques for analysing the performance of AIOLs have not been standardised and clinical studies have reported findings using a wide range of both subjective and objective methods, making it difficult to gauge the success of these implants. There is a need for longitudinal studies using objective methods to assess long-term performance of AIOLs and to determine if true accommodation is restored by the designs available. While dual-optic and curvature change IOLs are designed to provide greater amplitudes of accommodation than is possible with single-optic devices, several of these implants are in the early stages of development and require significant further work before human use is possible. A number of challenges remain and must be addressed before the ultimate goal of restoring youthful levels of accommodation to the presbyopic eye can be achieved.

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Diffractive Alvarez lens

Cited by 53 publications

References 2 publications

Metasurface Freeform Nanophotonics

Metasurface Freeform Nanophotonics

Miniature Solid Tunable Lenses and Their Applications: A Review

Accommodating intraocular lenses: a review of design concepts, usage and assessment methods

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